<!DOCTYPE html>
<style>
.container {
	height: 400px;
	overflow-y: hidden;
}

.item {
	height: calc(100% - 50px);
	min-height: calc(100% - 50px);
	box-sizing: border-box;
}

.item > div {
	height: 100%;
	overflow-y: auto;
	border: 1px solid black;
	box-sizing: border-box;
}
</style>
<p>crbug.com/580508: Should have a black border all round.</p>
<div class="container">
	<div class="item">
		<div>
		</div>
	</div>
</div>
